1. Field of the Invention
The present invention relates to a dielectric element such as a thin film capacitor, and a method for manufacturing the same.
2. Related Background Art
A dielectric element having a structure in which a dielectric is provided on an electrode is generally known. A typical example of a dielectric element is a thin film capacitor. Japanese Patent Application Laid-Open No. Hei 8-55967 discloses manufacture of a dielectric element having a low leak current density by annealing a laminated structure under an oxidation atmosphere at 500° C. or higher after sequentially laminating a lower electrode, a dielectric film, and an upper electrode on a substrate. Further, Japanese Patent No. 3188179 discloses a method for heating the laminated structure under an atmosphere at a pressure of 1 atm or lower after sequentially laminating the lower electrode, the dielectric film, and the upper electrode on the substrate.
The method in Japanese Patent Application Laid-Open No. Hei 8-55967 uses Pt as a material of the upper electrode and the lower electrode because the annealing temperature is comparatively high. However, since Pt is expensive, it is preferable if an inexpensive material having a high conductivity such as Cu, Ni, Al, or Ag whose oxidation temperature is low can be used for an electrode of a dielectric element. These metals, however, have a low oxidation temperature, and therefore, it is difficult to use them in the method in Japanese Patent Application Laid-Open No. Hei 8-55967, in which annealing is performed at comparatively high temperatures. It is possible to prevent oxidation if the annealing temperature is reduced, however, it is no longer possible, on the contrary, to sufficiently reduce the leak current density.